The conveying apparatus and general machinery structure for a hydrostatic bottle testing device to which the present invention is related is disclosed in U.S. Pat. No. 3,894,424 to Taylor et al entitled "On-line Pressure Testing System" and issued July 15, 1975. The disclosure and illustrations of this patent are incorporated by reference herein.
The above-referenced Taylor et al patent, for detecting the presence of undesirable bottles which had been previously hydrostatically loaded, utilized a photocell sensing device for determining whether or not a bottle had collapsed and therefore disappeared from view of the photocell or whether the bottle had cracked and therefore, had a liquid level therein which was lower than a predetermined standard level.
Theoretically, both of these conditions were electrically identical in that the photocell would see light under both of those conditions. On the other hand, a good container which was full of water and has not disappeared from the view of the photocell presented a different optical property and would preclude the generation of a reject signal due to the difference in response of the photocell to the presence of a water filled bottle.
The photocell was interrogated at a particular time in the test cycle to enable a reject signal, if generated, to drive a suitable reject mechanism to remove the undesirable bottle from a conveyor carrying the bottles being tested past the photocell and also, to activate air jet cleaning devices or the like to clear the debris off of the conveyor in the event of broken bottles and glass fragments or the like.
Upon operation of this testing device of Taylor et al, certain disadvantages due to problems of sensitivity, difficulties of fine adjustments, and criticality of timing with respect to bottle position and the interrogation signal for the photocell were noted and the need for an improved system of both undesirable bottle detection and rejection became apparent.
A system was desired in which the detection of the presence or absence of water pressure in a given bottle would occur as late as possible in the pressure cycle in that bottle as applied thereto by a hydrostatic pressure head such that a good container would have a significant and detectable pressure level therein while a container which had collapsed or cracked would have little or no pressure. Thus, the difference between a bottle with full integrity and one of undesirable or unacceptable integrity would be sufficiently substantial to provide a reliable measurement of that difference.
It is, therefore, an object of the present invention to provide an improved hydrostatic pressurization and detecting means for accurately determining the hydrostatic testing pressure in a bottle at a specifically desired point in the hydrostatic test pressure cycle.
Another object of the present invention is to provide a new and novel means for remembering the occurrence of a bottle of unacceptable integrity such that the unacceptable bottle can be free of the hydrostatic pressurization mechanism and in an unconstrained and more readily rejectable state prior to initiation of a reject cycle.
Still an another object of the present invention is to provide a new and novel reject control means for removing bottles of undesirable integrity from a hydrostatic test pressure device immediately downstream from the hydrostatic test pressure station.
Yet another object of the present invention is to provide a new and novel air jet conveyor cleaning apparatus for a hydrostatic bottle integrity testing mechanism which is synchronized and timed with the mechanical reject mechanism and the spacing of the bottles being tested on a conveyor means to maintain the conveyor clear and clean of glass fragments downstream of the reject station.
These and other objects of the present invention will become more fully apparent with reference to the following specification and drawings which relate to a preferred embodiment of the present invention.